Comparison of the torque of flat airgap synchronous couplings versus the magnetization direction of the magnets

A study of flat airgap synchronous couplings uses the analytical formulas of the tangential and radial components of the force between two permanent magnets. These formulas are applied to compare the torque transmitted by three different structures of flat airgap couplings. In the first, the magnets have a radial magnetization direction with respect to the rotation axis. This direction is tangential to the rotation axis in the second structure and parallel to the rotation axis in the third where the force Is computed with a semi-analytical method. The torque of the different couplings is studied and compared. The dependence of the torque on various parameters such as the number of pole pairs and the width, length, and depth of the magnets is also investigated. The analytical and semi-analytical methods used afford efficient optimization of the coupling structure with full compliance with practical and economic constraints.